One embodiment of the present invention comprises a metering device that is related to the Quadlogic ASIC-based family of meters (see U.S. Pat. No. 6,947,854, and U.S. Pat. App. Pub. No. 20060036388, the entire contents of which are incorporated herein by reference). Specifically, this embodiment (referred to herein for convenience as “Energy Guard”) is a multi-channel meter that preferably is capable of providing much of the functionality of the above-mentioned family of meters, and further provides the improvements, features, and components listed below.
Used in at least one embodiment, a MiniCloset is a 24-channel metering device that can measure electric usage for up to 24 single-phase customers, 12 two-phase customer, or 8 three-phase customers. Preferably connected to the MiniCloset are one or more Load Control Modules (LCMs), discussed below.
Energy Guard preferably comprises a MiniCloset meter head module and two LCMs mounted into a steel box. Relays that allow for an electricity customer to be remotely disconnected and reconnected, along with current transformers, also are mounted into the box. See FIG. 1.
Upon installation, an electricity customer's electricity supply line is tapped off the main electric feeder, passed through the Energy Guard apparatus, and run directly to the customer's home. The construction and usage of the Energy Guard will be apparent to those skilled in the art upon review of the description below and related figures. Source code is supplied in the attached Appendix.
Energy Guard meters preferably are operable to provide:
(A) Remote Disconnect/Reconnect: The meter supports full duplex (bi-directional) communication via power line communication (“PLC”) and may be equipped with remotely operated relays (60 amp, 100 amp, or 200 amp) that allow for disconnect and reconnect of electric users remotely.
(B) Theft Prevention: The system is designed with three specific features to prevent theft. First, an Energy Guard apparatus preferably is installed on a utility pole above the medium-tension lines, making it difficult for customers to reach and tamper with. Second, because there are no additional signal wires with the system (i.e., all communication is via the power line), any severed communication wires are immediately detectable. That is, if a communication wire is cut, service is cut, which is readily apparent. A third theft prevention feature is that the meter may be used to measure the transformer energy in order to validate the measured totals of individual clients. Discrepancies can indicate theft of power.
(C) Tamper Detection: The Energy Guard preferably provides two modes of optical tamper detection. Each unit contains a light that reflects against a small mirror-like adhesive sticker. The absence of this reflective light indicates that the box has been opened. This detection will automatically disconnect all clients measured by that Energy Guard unit. In addition, if the Energy Guard enclosure is opened and ambient light enters, this will also automatically disconnect all clients measured by that Energy Guard unit. These two modes of tamper detection are continuously engaged and alternate multiple times per second for maximum security.
(D) Reverse Voltage Detection: In some cases, a utility company can disconnect power to an individual client and that client is able to obtain power via an alternative feed. If the utility were to reconnect power under these conditions, damage could occur to the metering equipment and/or the distribution system. Energy Guard preferably is able to detect this fault condition. The Energy Guard can detect any voltage that feeds back into the open disconnect through the lines that connect to the customers' premises. If voltage is detected, the firmware of the Energy Guard will automatically prevent the reconnection.
(E) Pre-Payment: Pre-payment for energy can be done via phone, electronic transaction, or in person. The amount of kWh purchased is transmitted to the meter and stored in its memory. The meter will count down, showing how much energy is still available before reaching zero and disconnecting. As long as the customer continues to purchase energy, there will be no interruption in service, and the utility company will have a daily activity report.
(F) Load Limiting: As an alternative to disconnection for nonpayment or part of a pre-payment system, Energy Guard meters can allow the utility to remotely limit the power delivered to a set level, disconnecting when that load is exceeded. If the customer exceeds that load and is disconnected, the customer can reset a button on the optional remote display unit to restore load as long as the connected load is less than the pre-set limit. Alternatively, clients can call an electric utility service line by telephone to have the service restored. This feature allows electric utilities to provide electricity for critical systems even, for example, in the case of a non-paying customer.
(G) Monthly Consumption Limiting: Some customers benefit from subsidized rates and are given a maximum total consumption per month. The Energy Guard firmware is capable of shutting down power when a certain consumption level is reached. However, this type of program is best implemented when advanced notification to customers is provided. This can be achieved either with a display in the home whereby a message or series of messages notifies customers that their rate of consumption is approaching the projected consumption for the month. Alternatively (or in conjunction) timed service interruptions can be programmed so that as the limit is approaching, power is disconnected for periods of time with longer and longer increments to notify the residents. These planned interruptions in service act as a warning to customers that their limit is nearing so that they have time to alter their consumption patterns.
(H) Meter Validation: The integrated module of the system preferably is removable. This permits easy laboratory re-validation of meter accuracy in the event of client billing disputes.
(I) Operational Benefits for Utility: The Energy Guard has extensive onboard event logs and diagnostic functions, providing field technicians with a wealth of data for commissioning and trouble shooting the electrical and communication systems. Non billing parameters include: amps, volts, temperature, total harmonic distortion, frequency, instantaneous values of watts, vars and volt-amperes, V2 hrs, I2 hrs, power factor, and phase angle.
These features and others will be apparent to those skilled in the art after reviewing the attached descriptions, software code, and schematics.
In one aspect, the invention comprises a device for measuring electricity usage, comprising: means for remote disconnection via power line communication; means for detection of electricity theft; means for tamper detection; and means for reverse voltage detection.
In another aspect, the invention comprises an apparatus for multi-channel metering of electricity, comprising: (a) a meter head operable to measure electricity usage for a plurality of electricity consumer lines; (b) a transponder in communication with the meter head and operable to transmit data received from the meter head via power line communication to a remotely located computer, and to transmit data received via power line communication from the remotely located computer to the meter head; and (c) a load control module in communication with the meter head and operable to actuate connection and disconnection of each of a plurality of relays, each relay of the plurality of relays corresponding to one of the plurality of electricity consumer lines.
In various embodiments: (1) the apparatus further comprises a tamper detector in communication with the meter head; (2) the tamper detector comprises a light and a reflective surface, and the meter head is operable to instruct the load control module to disconnect all of the customer lines if the tamper detector provides notification that the light is not detected reflecting from the reflective surface; (3) the apparatus further comprises a box containing the meter head, the load control module, and the relays, and wherein the tamper detector comprises a detector of ambient light entering the box; (4) the apparatus further comprises a box containing the meter head, the load control module, and the relays, and wherein the box is installed on a utility pole; (5) the apparatus further comprises means for comparing transformer energy to total energy used by the consumer lines; (6) the apparatus further comprises means for detecting reverse voltage flow through the consumer lines; (7) the apparatus further comprises a computer readable memory in communication with the meter head and a counter in communication with the meter head, the counter corresponding to a customer line and operable to count down an amount of energy stored in the memory, and the meter head operable to send a disconnect signal to the load control module to disconnect the customer line when the counter reaches zero; (8) the apparatus further comprises a computer readable memory in communication with the meter head, the memory operable to store a load limit for a customer line, and the meter head operable to send a disconnect signal to the load control module to disconnect the customer line when the load limit is exceeded; (9) the apparatus further comprises a computer readable memory in communication with the meter head, the memory operable to store a usage limit for a customer line, and the meter head operable to send a disconnect signal to the load control module to disconnect the customer line when the usage limit is exceeded; (10) the transponder is operable to communicate with the remotely located computer over medium tension power lines; (11) the apparatus further comprises a display unit in communication with the meter head and operable to display data received from the meter head; (12) the display unit is operable to display information regarding a customer's energy consumption; (13) the display unit is operable to display warnings regarding a customer's energy usage or suspected theft of energy; and (14) the display unit is operable to transmit to said meter head information entered by a customer.